The accessibility of potable water is fundamental to public health. A private for-profit company is installing kiosk-based drinking-water systems in rural and peri-urban villages in Ghana, and we evaluated their performance. Preceding an observational study to measure the effect of these kiosks on the incidence of water-related disease in recipient communities, we conducted ethnographic research to assess local water-related practices and the ways these practices would affect adoption of the new technology. We conducted fieldwork in two communities in Ghana and interviewed stakeholders throughout the water sector. Our findings illustrate the complexity of water-related behaviors and indicate several factors that may sustain disease transmission despite the presence of the new technology. This formative ethnographic research also improved the precision of our subsequent evaluation of the intervention by providing a site-specific, culturally-appropriate knowledge base. This study demonstrates the value of incorporating qualitative research techniques into evaluations of water-related projects.